A recent face-lift has brought with it subtly smoothed-out styling, including a new front bumper, reshaped front and rear lights and a wider rear window that gives a less bulbous shape at the back.

However, the basic nuts and bolts remain the same, which means a 4.8-litre turbo V8 still drives all four wheels through Porsche's seven-speed PDK automatic gearbox.

What’s 2014 Porsche Panamera Turbo like to drive?

The twin-turbo V8 engine pumps out a massive 512bhp, so even though the Panamera weighs in at almost two tonnes, it’ll still comfortably out-accelerate a 911 Carrera S.

Just as impressive is how the Turbo makes this performance seem so undramatic. Even on a wet road you simply plant the throttle and the four-wheel-drive system slingshots you towards the horizon with no fuss whatsoever.

The Turbo isn't all about straight-line speed, though. Yes, it’ll do 190mph, but it's also astonishingly agile for such a big and heavy car. It turns in sharply and combines immense sideways grip with very little body lean, while the precise steering gives you the confidence to really attack corners.

In fact, if we have one criticism, it's that the Turbo is so unflappable it leaves you a bit removed from the driving experience - rather than feeling that you're at the heart of the action.

If you're planning to use the Panamera's mile-munching abilities to cross continents, you may also get a bit fed up with stopping for fuel. The Turbo has a huge 100-litre tank, but an average of 27.7mpg gives it a theoretical range of only around 600 miles. Of course, you won't get anywhere near that if you're pushing on. The diesel version of the Panamera, meanwhile, can officially average 44.1mpg, so can manage 770 miles between fill-ups.

Stick with the standard 19-inch alloys and Turbo rides remarkably smoothly. This is partly thanks to Porsche’s Active Suspension Management (PASM) system, which lets you stiffen and soften the dampers at the touch of a button. In fact, in the softest of three available settings, the Porsche soaks up bumps better than most family hatchbacks.

Leave the gearbox in Drive and the standard PDK automatic gearbox flicks through the gears smoothly. Alternatively, take control using chunky steering wheel-mounted paddles and the ‘box responds immediately to your every command.

The rear cabin accommodates two people in very comfortable, individually adjustable seats. The boot is fairly shallow, but access is good and the load bay is wide enough to swallow a set of golf clubs without you needing to fold the rear seats.

This is clearly a luxurious car and it shows. You feel properly pampered behind the wheel, with the centre console bisecting the cabin and housing most of the switchgear, and a standard colour touch-screen dominating the shallow, upright dashboard.

Crisp, easy-to-read dials provide you with vital driver information, while the touch-screen offers whatever other useful information you might want, from navigation instructions to how many miles you have left in the tank.

All the cabin materials feel appropriately sumptuous, and although the dashboard is a bit button-heavy in areas, most of the controls are easy to get the hang of.

To go some way towards making up for the huge price, the Turbo has plenty of standard kit, including sat-nav, xenon headlights, a powered tailgate, keyless entry and start, and front and rear parking sensors. However, you can easily add five figures to the price by ticking boxes on the seemingly endless list of options.

Should I buy one?

The Panamera makes way more sense in diesel form. It costs a whopping £45,000 less to buy, yet still delivers crushing real-world pace and supreme comfort, along with a much better fuel economy.

However, if you really must have proper supercar pace from your luxury car and are prepared to pay through the nose to get it, the Panamera Turbo is a better buy than an Aston Martin Rapide or a BMW M6 Gran Coupe.

That said, a Mercedes CLS63 AMG is almost as rapid and refined, more engaging to drive thanks to its rear-drive layout, and significantly cheaper at £82k.

So, although it's impossible not to marvel at the Turbo’s breadth of abilities, there are much cheaper ways to enjoy almost as much luxury and performance.